It is standard in a paper plant to unroll huge rolls of paper, often up to 8 m long and weighing as much as 50 ton, then Longitudinally slit the paper and roll it up into individual smaller rolls. To this end the starting rolls that are carried on heavy steel shafts are unwound in an unwinding station at high rates of speed and fed through various slitters to a winding station.
As described in WO 90/10591 of H. Schonmeier et al published Sep. 20, 1990 (see also German 2,118,984 published Nov. 9, 1972 and German 3,440,107 of K. Thievessen published May 22, 1986), a splicing drum movable adjacent the unwinding station has a cylindrical surface that can be engaged against the paper web as it moves away from the paper roll. The splicing drum has an axially extending and radially outwardly open groove in which is provided a cutter and which is flanked by a pair of suction regions. Thus, when this splicing drum is pressed against the web, one of the suction regions can be activated to hold the web against the roll surface as the cutter transversely slits across the web. This leaves the trailing edge of the outgoing web suctionally adhered to the splicing-roll surface so that the depleted roll can be replaced with a full fresh roll of paper whose free end is typically provided with an outwardly facing adhesive strip. Then the splicing drum is pressed against and rolled off on the new roll to adhere the trailing end of the now replaced paper roll to the free end of the fresh roll, and the unwinding/winding process is completed.
In order to tension the paper web the splicing drum is provided with a gripper in the cutter slot. This gripper is formed as a cable spanned between a pair of arms that can pinch the suctionally held paper end against one edge of the slot while the splicing drum is rotated to put the desired tension in the web. It is fairly common for a new supply roll to be wound oppositely to the roll being taken out and it is clearly impractical to turn around a huge roll weighing many tons, so the splice arrangement must be able to adapt to takeoff from rolls wound in different directions. Hence the gripper can move against either edge of the slot and the drum can be rotated in either direction.
The main disadvantage of this arrangement is that the web is not held very strongly, so that it can slip out and be dropped by the splicing drum. If enough force is used to clamp it securely, the chance of tearing or cutting the web is great.